In the past, a wireless-network compatible projector has been known. According to the projector of this kind, an image on a personal computer can be enlargedly displayed using the projector without connecting them to each other (e.g., Japanese Patent Publication No. 2003-69923).
As the wireless network, there are two broad types of connection system. One is a system called ad-hoc network, which is a small-scale network in which individual wireless devices are directly connected to each other. The other is a system called infrastructure network, in which individual wireless devices such as a projector perform connection to one of wireless devices as access points, and the access points are connected to each other with a wired network, thereby making it possible to form a large-scale network.
In the ad-hoc network, since connectable devices are limited due to the wireless access range, it is easy to determine the projector adjacent to the personal computer. Therefore, mechanisms for easily searching and connecting the adjacent projector are widely used as, for example, “easy installation.”
However, in network systems built up using an infrastructure network of the related art, there arises a problem that it is not achievable to determine whether or not the projector is adjacent from the protocol transmitted on the network, and therefore, it is not achievable to discriminate the adjacent projector.